Transmission mechanism.



Patented Feb. 26,1918.

GEQRGE M. Id'ill' F CHICAGU, ILLINOIS, ASSIGNOR 01E ONE-HALF T0 CHARLES A.

tit

BROWN, 01E HINSDME, ILLINOIS.

TRANSMISSION MECHANISM.

instance.

Specification of Letters Patent.

Patented Feb. 8%, TNT.

Application filed. .11 une 12, 1914. fierial 1t 0. 8%,605.

- concise, and exact description, reference bestarter a very rapid movement of ing had to the .accompanying drawings, forming a part of this specification.

This invention relates to engine starters.

In modern automobile construction it is common to employ a dynamo electric machine for starting the engine and for charging the batteries when the engine is running;

Dificulty has been experienced in providing suitable transmission means between the starter and the engine. This transmission must fulfil the requirements of two classes of service which are markedly difierent.

When the starter drives the engine a slow movement of great power is required as the engine is stifi and the periods of compression ofier great resistance to turning of the engine shaft. When the engine drives the greatly re duced power is required, but due to the two requirements it has. become the practice among automobile engineers to employ two separate units at an increased cost and an undesirable increase of weight and complicate mechanism.

It is desirable to use only a single unit and to employ a single transmission between the engine and the starter. Heretofore, gears or chains and sprockets have been employed as they have been practically the only means for securing a positive driving action when starting; but these devices are objectionable at the high engine speeds attained under ordinary o erating conditions. Belts have been tried ut are found to be unsuitable asthey are too weak mechanically for the speed at starting, and if made sufficiently strong and tight to act on starting duty, ey cause friction and wear on the bearings when the engine is running at high speed.

The object of the present invention is to provide improved driving means between the starter and the engine. Another object is the provision of automatic means for increasing the adhesion of the driving belt to the transmitting wheels when the starter is operating the engine and for decreasing the same when the engine drives the starter. s

A still further object is a provision of automatic means for tightening a power belt, which means will be brought into action automatically when the starter drives the engine and which will be automatically dropped out of action when the engine drives the starter.

Accordingly, in my invention, a flexible chain belt is used as a transmission means and automatic means is provided for increasing and relieving the tension in the belt at the proper times. i

In the accompanying drawings--' Figure 1 is a view of an engine connected to a starter employing a driving mechanism embodying the present invention showing the action which occurs when the starter is driving the engine; N

Fig. 2 is a view of the same showing the mechanism in the position assumed when the engine drives the starter;

Fig. 3 is a view of the type of grooved pulley employed on both the engine and the starter shafts;

Fig. 4c is an end view of a link of the flexible chain belt;

Fig. 5 is a side view of the same;

- Fig. 6 is a side view of a modification of the tightening mechanism;

Figs. 7 .and 9 are side views of other modifications;

Fig. 8 is a top view of the starter showing the attachment of the tensioning means.

In Fig. 1 the engine 1 is represented diagrammatically as connected by means of the belt 2 to the starter (not shown). A grooved pulley-or sheave 3 is attached to the engine shaft and a similar but smaller sheave or I pulley 4: is connected to the starter shaft 5.

Arms 8'and9 support a pin 10 in proximity to the pulley 4 on the starter shaft. he arm 8 is rigidly fastened to the frame of the starter 7 to maintain the arms 8 and 9 in a fixed position.

' The belt 2 (best shown in Figs- 3, 4 and 5) consists of a chain made up of bearing links 15 and connecting links 16. The hearing link has connected thereto a plate 17 secured by a saddle member 18 of tapered configuration. An asbestos friction or bearing pad 19 covers the sides of the saddle member 18 and presents a wearing surfaceof great resistivity to the tapered side of the g It is secured to the saddle 'member 18 by bent-over portions 20 of the saddle member 18. i

A T-shaped lever 22 bears the rollers 23 and 21 upon the arms 25 and 26. This lever is pivoted on the pin 10 and has alimited rotating movement on said pin. A pin 27 is arranged to come in contact with the links 8 and 9 to prevent the member 22 from dropping below a certainposition as shown in Fig. 2.

The operation of the device is as follows:

When the starter is driving the engine as shown in Fig. 1, the parts will be rotated in a counter-clockwise direction and the lower span of the belt will be drawn taut between the pulleys 3 and 4:. This action tends to rotate the member 22 about the pin 10 as the lower span of the belt presses the roller 24 upward. The arm 25 is of greater length than the arm 26 and, as a consequence, the upper span of the belt '2 will be stretched by the raising of the member 22. This keeps both sides of the belt tight and draws the belt into the groove of the pulleys, the natural adhesion of the belt to the pulleys being insufficient to withstand the great strain required to start the engine. As soon as the engme begins to operate, the starter will be driven by the engine and the upper span of the belt 2 will be drawn taut and the'lower span will be slackened. As this occurs, the member 22 rotates in a contra-clockwise direction about the pin 10,

and, due to the greater amount of movement of the arm 25 over that of the arm 26 the pin 27 engages the shoulders on the arms 8 and 9 and is held out of contact with both spans of the belt and no drag results as is customary in the usual belt tightening mechanism. This is especially desirable as the engine operates at very high speeds and any amount of friction, however small, would materially reduce the efiiciency of the transmission device.

In the modification shown in Fig. 6 the arms 8 and 9 are rotatable on the shaft 5 of the starter and the lever 22 is normally held out of contact with the belt by means of the spring 30. This spring holds the arm against a pin 31 and thereby separates the electromagnet 32 which is connected 'to the pin 10 by means of the rod 34 away from its armature 33. The electromagnet 32 is in series with the starting switch for closing the circuit of the starting motor 7 and as soon as the starter draws current to increase the tension on the lower span of the belt the electroma et 32 breaks the knuckle formed by the 8 and 9 with the lever 22 and forces the lower roller 24 against the belt 2 causing the lever 22 to swing about this roller as a pivot and to force the upper roller against the belt as indicated in the dotted lines.

In the modification illustrated in Fig. 7 the arm 22, instead of bearing a roller at its upper end, is connected with a lever 35 pivoted at the point 36 and bearing at its outer end the roller 23. In this manner the upper span of the belt is pressed down when the starter is driving the engine and the lower span of the belt is drawn taut. The operation of the structure shown in Fig. 7 is identical with that shown in Figs; 1 and 2 except that the lever 35 has been introduced to exert the pressure upon the belt from above to press the same inwardly instead of pressing the same outwardly.

,The structure of Fig. 9 is similar to that of Fig. 6. Instead of operating the device by means of the electromagnet the arm 22 may be moved by means of an extension of the startin switch shown as rod 37, to tighten the be t when the switch is closed.

It can be seen from the above that I have provided a transmitting means which automatically varies its action to suit the different classes of service to which it is subject. Under the driving action of the starter the belt is tightened and forced into the groove 21 of the pulleys. As soon as the engine operates to drive the starter tension on the belt is automatically released, the rollers drop out of contact with the belt and no drag is exerted on the transmission means when the engme is running.- It is obvious that a very great advantage and marked efficiency of transmission is secured thereby.

Although the invention has been illustrated with reference to the details of a particular embodiment it is not intended thereby to limit the invention except as limitations are embodied in the appended claims;

What I claim as new and desire to secure by Letters Patent of the United States is:

1.- In an engine starting mechanism, an engine having a shaft, a starter having a shaft, a pulley attached to the engine shaft, a pulley attached to the starter shaft, a belt connecting said pulleys and automatic means for tightening the belt when the. starter drives the engine, and for releasing the tension on the belt when the engine drives the starter.

2. In an engine starting mechanism an engine shaft, a starter shaft, a taper grooved pulley attached to the engine shaft, a taper grooved pulley attached to the starter shaft, a tapered chain belt connecting said pulleys, the links of said chain bearing non-metallic friction means and automatic means for forcing the belt into the taper grooves when 130 women it the starter drives the engine and for releasing the tension on the belt when the engine drives the starter.

\ 3. In an engine startin system, a starter shaft, a pulley upon sai shaft, an engine shaftand a pulley mounted thereupon, a belt connecting said pulleys, a lever automatically operated when the starter drives the engine for tightening the belt between said pulleys, said lever having operating arms of difi'erent lengths. 1

4'. In an engine starting system, a starter shaft having a pulley thereupon, shaft having a pulley mounted thereupon,'a belt connectlng said pulleys, a lever having arms of difierent length pivoted at one end to a fixed point and, having a roller at one point adapted to bear against one span of said belt when the said span is under tension and means connected to said lever for causing the other span of said belt to be tightened when the said first span 1s under tension from driving.

5. In an' engine starting system, a starter shaft having a pulley thereupon, an engine shaft havin a pulley mounted thereupon, a belt connectmg said pulleys, a lever having arms of difierent length pivoted at one end to a fixed point and having a roller at one point adapted to bear against one span of said belt when the said span is under tension and means connected to said lever for causing the other span of said belt to be tightened when the said first span is under tension from driving, said lever mechanism being entirely free from said belt'when the other span of said belt is under tension from :driving by the engine.

6. In an engine starting system, a starter shaft having a pulley thereupon, an engine shaft having a pulley mounted thereupon, a belt connecting said pulleys,a leverhaving arms of different length pivoted at one end to a fixed point and having a roller at one point adapted to bear against one span of said belt when the said span is under tension and means connected to said lever for causing the other span of said belt to be tightenedwhen the said first span is under tension from driving and a projection on said lever adapted to port when said other from driving.

7 In an engine starting system, a starter engage the fixed supan engine span is under tension shaft, a pulley thereupon, an engine shaft, a pulley mounted thereupon, both of said pulleys bearing tapered grooves, a tapered chain belt adapted to fit said grooves connecting said pulleys, a lever having arms of different length pivoted at one end to a fixed point and having a roller at one point hearing against one span of said belt when the sald span is under tension, and means connected to said lever for causing the other span of said belt to be tightened when the said first span is under tension from driving.

8. In an engine startingsystem, a starter shaft, a pulley thereupon, an engine shaft, a pulley mounted thereupon, a belt connecting said pulleys, a lever pivoted at one "end to a fixed point, said lever bearing a roller at its outer end and a second roller intermediate the ends, said second roller engaging one span of the belt when the same is under tension from the starter driving the engine, and thereby forcing said first roller against the loose span of the belt to tighten the same, said rollers being out of engagement withsaid belt when the engine drives the starter.

9. In a starting system, a starting shaft, bearing a pulley,'an engine shaft bearing a pulley, abelt connecting said pulleys, a belt tightener having a roller bearing against the taut span of the belt when the starter drives the engine, an arm connected to said roller and bearing a second roller for ti htening the loose span of the belt, said 1 elt tightener being inoperative when the one drives the starter.

10. In a starting system, a starting shaft, bearing'a pulley, an engme shaft bearing a pulley, a belt connecting said pulleys, a belt tightener havin a roller bear against the taut span 0% the belt when the starter drives the engine, an arm connected to said-roller and bearing a second roller for tightening the loose span of the belt, said rollers being out of contact with both spans of said belt when the engine drives the starter. I

In witness whereof, I hereunto subscribe my name this 28th day of May, A. D. 1914.

GEORGE M. i 

